Burglar alarm and lock therefor



June 2, 1931.

-E. BELLMAN BURGLAR ALARM AND LOCK THEREFOR Fi-led NOV. 26, 1928 EDWARDBELLMAN, OF ROOIFOBD, ILLINOIS BURGIAR ALARM AND LOCK THEBEFORV.Application led November 28, 1928. Serial No. 821,930..

This invention relates to a burglar alarm and lock therefor.

Objects of this invention are to provide a novel form of burglar alarmin which a lock I 5 is employed, controlled by a removable key forthrowing into or out of operation, the entire alarm system,so that theowner of the house or building in which it is installed may readilythrow into or out of o eration, the entire system, with no more e ortthan is required to lock a door.

' Further objects are to provide a device which is so constructed thatit will present no screws or other members which could 5 he removed, butinstead, which presents a 'plate 'tree from any such fastening means andwhich is so made that if it is attempted to pry the plate loose 'fromthe rest of the apparatus in order to pick the lock., that this 9operation itself will start the alarm; the alarni system being soconstructedthat the alarm continuously sounds after it is once started.Entrance must be made to the inside at a designated placey to stop thealarm. g5 The lrey to the lock will turn the alarm on, but not ed, afterthe hell has started.

Further objects are to provide a device which is easy to construct andisvery easy to install, and which is so made that no 3@ thought isrequired on the part of the user other than merely inserting a key andoperating the lock.

An embodiment of the invention is shown in the accompanying drawings, inwhich:

v Figure l is a rear View oil the loclrwith parts broken away and insection, such view showing a portion of the systeni..

Figure 2 is a longitudinal sectional view through the lock. 4G Figure 3is a transverse sectional view on the line 3 3 of Figure l.

Referrin to the drawings, it will be seen that the loo comprises anouter metal plate l. This metal plate is provided with a plu- 45 ralityof threaded pins 2, which are perinanently set in the plate on its innerside and secured in an permanent manner, as by soldering, wel ing or inact, i n any other way. These pins serve to position an insu- 50 latingsheet 3, which is positioned to the inner face of the plate l. Thisinsulating sheet has positioned thereon a metal plate 4, which isprovided with a centrally bulged portion, an with rounded ends, asindicated in vFigure l. The metal plate 4 is provided `5l-5 withapertures which are counter-sunk to receive the tapered heads ofrearwardly projecting bolts 5, by means of which the lock may be securedin place. This metal plate is held in place by means of an insulating'plate 6, (see Figures l, 2 and 3). The insulatingplate is held in placeby the threaded ring-nut 7 of the tumbler carryin portion or barrel 8 ofthe lock. 4rlhis loc may be of standard construction and may be providedwith a hey-hole in the usual way, adapted to receive an operating key.

l' llie rotatable portion at the rear of the loclr carries a cam member9 (see lili res l and 2), which is equipped with a heyehole into'whichthe lrey enters when inserted in the lock, so that when the lrey isoperated, the cani'portion 9 operates and controls contacts, hereinafterto be described.

A relatively short spring contact l0 is secured 'by means of bolts ll tothe insulating plate 6. A relatively longer sprin Contact l2 is alsosecured by means of bo ts 13 to the insulating plate. The longer4contact member l2 is movable and normally engages the contact l0;however, when the lock is unlocked, the ca'in member 9 or the lockmember moves the spring contact member l2 outwardly away from the springcontact ld, and the system is now rendered inoperative. @5 -When it isdesired to throw the system into operation, the user merely inserts hiskey and operates the loclr as it he was lochng it. This rotates the cammember 9 in a clock@ wise direction, as viewed in Figure l, and @ilallows the contact l2 to engage the contact 10. The contact l2 isconnected to a' small metal clip le, which is in turn con? nected to theinner metal casing l5 oit the loclr. rlhis inner metal casing is alsoconnected to a paiir of inwardly projecting metal lingers 16, orstationary Contact members 2 (see Figures l and 2), which overhan themetal plate d. l

T e bolts 2, or threaded pins, pass through the inner Han s of 'the rearcasing 15 and flexible cable, having a pair of conductors Vsus 17 and 18and having the metal sheath 19. This metal sheath may be merel a wrappedwire surrounding the insulated conductors 17 and 18. It is connected tothe plate 4,

-so that the metal sheath itself forms one portion of a circuit,hereinafter to be described. One of ythe conductors, 18, is connected tothe sprin contact'member or movable member 12 an thus to the clipsorjcontact members 16 of the front plate. The other conductors, 17, ofthe ca le, is connected to the contact member 10. l

' It is obvious that a three-wire cable could be employed, but it isfound cheaper to use the sheath of the armored cable as one of theconductors, thus cutting down the expense and also serving an additionalpurpose, which will hereinafter appear.'

The conductor 17 is connected by means of the wire 20 to a plurality ofmovable contact members,.as lndicated at 21 and` 22,v

of a lurality of alarm units. These contact mem ers are covered, thecover being remov-.

able only in formin a contact so that when the s stem is turne on thealarm must respon if covers are removed. The stationary contacts 23 and24 for such 'units are connected b means of a conductor 25 to the metalsheat 19.

Further, the wire 25 is connected to one side of a battery 26 and alsoto one side of an `electrical bell or other alarm member 27.

The other side of thebattery 26 is connected through the coils of anelectro-magnet 28 to p a wire 29 leading to the conductor 18 of thecable. It is, of course, to be understood that the cable itselfconstitutes the major portion of the conductors 20 25 and 29, and may berun through the buildin as a single means, havin these three con uctingportions, as descri ed. One side of the bel 27 is connected to a droplever or trip 30, held in place by the armature 31 of the electro-magnet28. When this electro-magnet is energized, the l'ever or catch drops andconnects with a wire 32 leading to one side of the battery. The otherside of thel battery is connected to the bell, as indicated in Fi re 1,and consequently, a local circuit, inclu ing the bell, or other soundingdevice, and batterly, is established. Y

t is apparent that the member 21 may be controlled by a wire or thread,as indicated I at 33, so that when this thread is touched or broken bythe unauthorized entry of a person, or by burning, that the member 21engages the contact 23 and consequently sounds the alarm.

Further," it is apparent that the member 22 4 may bear against a windowsash or door, in-

dicated by the reference charactery 34 in Figure 1, and when said windowsash, or other movable member is moved, that the -member 22 engages `thecontact 24e, thus sounding the alarm.l I

Further than this', if a burglar attempts to render the alarm systemuseless by cuttm through the wire lwound Vor 'metal sheat cable, he willYestablish a connection between the conductor 17 or 18 and the metalsheath,

'which is connected through the conductor 25 to the battery. Thus, thealarm is sounded whenever the cable is cut. l

Further, it is to be noted that if an attempt is made to pry the frontmetal plate off, that this will cause the contact-member 16, rigidlysecured thereto, to engage the metal plate 4 and consequently sound thealarm.

It is, of course, obvious that there are timeswhen it is desired torender this alarm slyl'stem inoperative, as, for linstance, when t ehouse is in normal use and when people are entering or leavingY thehouse, or operatlng the windows protected by this system. This isreadily accomplished by unlocking the lock or master c ontrol member.However, whenever the occupant desires to throw the alarm into activecondition, it is merel necessary for him to lock the lock; hence, 1t isa sim le matter to throw the alarm into orout o use. J

It will be seen further, that a very sim le and highly effective alarmhas been provi ed by this invention, and it will be seen that a novelform of master control member or lock has been provided, which4 can notbe tamperedl with without setting olf the alarm.

Nothing can stop the alarmafter it has started except entrance tobuilding to the .provided place, such as the magnetic drop Although theinvention has been described' in considerable detail, such descri tionis intended as illustrative rather than limiting as the invention may bevariously embodied and as the scope of such invention is to bedetermined as claimed.

I claim 1.'In an alarm system having three conductors,.a lockcomprisingan outer plate,

,' a pair of contact members connected to two of said conductors, one ofsaid two conductors being connected to said metal plate, a cam membercontrolled by said lock for operating said contact members, and meanslll . 55 tact with each other lconnected to the third conductor andladapted to contact with a portion o the lock connected to one of saidtwo conductors, when the lock is pried loose.

2. In an alarm system having a metal sheathed, two-conductor cable, thecombination of a lock'having an outer plate, an inner metal plateinsulated therefrom, said inner metal plate being connected to themetalsheath of said cable, the outer metal plate having contact bracketsnormally out of contact with and over-hanging the inner metal plate,said outer metal plate bein connected to one of the two conductors osaid cable, a sprin contact member connected to such conuctor, a secondspring Contact member adapted to engage said first mentioned contactmember and connected to the other conductor of said cable,'and meansoperated by said lock for operating the Contact members. 3. In an alarmsystem having a metal sheathed, two-conductor cable, the combination ofa lock havin an outer plate, an inner metal plate insu ated therefrom,said f inner metal plate being connected to the metal sheath of saidcable, the outer metal plate having contact brackets normally out ofcontact with and over-hanging the inner metal plate, said outer metalplate bein connected to one of the two conductors o said cable, a, sprincontact member connected to such con uctor, a second spring contactmember adapted to engage sai first mentioned contact member and connected to theother conductor of said cable, and means operated by saidlock for operating the contact members, said means comprisin a cammember carried by the barrel of sai lock and adapted for actuation by. akey.

4. A lock for an alarm system comprisin an outer metal plate, threadedins secure thereto and projecting inward y from the inner face of saidmetal plate a metal cover metal plate and said contact members and outof contact with both said outer plate and said contact members, aninsulating vplate mounted inside of said inner metal plate, springcontact members urged toward contact with each other, and cam meanscontrolled byl said lock for spring contact members, sai inner metalplate being held in osition with reference :go said outer metal p ate byinsulating memers, inner metal plate and adapted to'securesaid lock inplace.

In testimony that I claim the fore oing I have hereunto set my hand atRockiord, in the county of Winnebago and State of Illinois. v

EDWARD BELLMAN.

carried by said pins, a pair o contact mem- A i bers carried by saidpinsA and spaced inwardly from said outer plate, an inner metal platepositioned between said outer metal plate and said contact members andout of contact with both said outer plate and said contact members aninsulating plate mounted inside of said inner metal plate, springcontact members urged toward conand cam means controlled by said loclrfor operating said spring contact members.

5. lock for an' alarm system comprisin an outer metal plate, threadedpins secured thereto and projecting inwardly from the Ainner face ofsaid metal plate, a metal cover .carried by said pins, a pair o-contactmembers carried by said pins and spaced inv and attaching screws carriedby said operating said eov

